High resolution and high sensitivity optically activated cursor maneuvering device

ABSTRACT

A cursor-manipulating device comprising a light diffusing surface, for example a Lambertian surface, covering a cavity containing a light source and an image sensor, wherein the cursor-manipulating device is a touch pad like device. The image detector senses the touching of the outer surface of the cursor-manipulating device with a pointing device, for example a finger, in which the outer surface comprises a light diffusing surface that allows the image sensor to capture and track an image of the pointing device touching the light diffusing surface in order to control a cursor of an electronic device. Multiple touching devices, like fingers, can be used to control simultaneous events on the screen of an electronic device, e.g. a notebook PC, cellular phone, game device and a GPS device.

This application claims priority to Provisional Patent Application Ser.No. 61/571,514, filed on Jun. 29, 2011, which is herein incorporated byreference in its entirety.

TECHNICAL FIELD

The present invention relates generally to portable electronic productsand more particularly to a cursor-maneuvering device.

BACKGROUND

Various kinds of electronic devices, e.g. notebook personal computers,cell phones, global positioning devices, as well as electronic gamingdevices, rely on the touching of a flat panel, which may be a touch pador a display screen of the electronic device. Two of the most popularsensing technologies used are resistive and capacitive sensingtechnologies, which provide users a convenient way to control theelectronic devices as opposed to a mouse connected by a USB cable to theportable electronic device. However, the lack of positioning accuracy bya pointing device, e.g. a finger or a pointing stylus, tends to limitthe use in an office environment.

Although, these electronic devices provide an advantage by beingportable, it is difficult for them to be used in an office environmentwhere the lack of positioning accuracy limits their use for data entrysuch as a word processor document or a spreadsheet where positioningaccuracy is important. FIG. 1 of prior art shows a flat panel touchscreen of a cellular phone commonly know as a smart phone 8, whereuponthere are a number of relatively large icons, which are displayedsimultaneously, that represent programs that can be activated whenselected. The number of icons is a compromise between allowing a largenumber of them to be displayed at once and a size of each icon necessaryto allow the user to be able to select them with the individual'sfinger. FIG. 1 shows an approximate size of a fingertip 9, which whenmisplaced can attempt to select up to four programs simultaneously.

The smart phone 8 shown in FIG. 1 uses a capacitor that lies behind thetouch screen of the smart phone. When the surface of the smart phonescreen is touched the capacitance of the capacitor is disturbed causingcharge on the capacitor to change and current to flow into sensorsusually positioned at each of the four corners of the smart phone. Thechange in current flow into these four sensors is then analyzed todetermine the approximate location of the touch point of the user'sfinger. The resulting analysis only needs to be accurate enough todefine an icon location, which can be seen from FIG. 1 has a fairlybroad dimensional location; and therefore allows a fairly broadinaccuracy in the calculated prediction of the location of the user'sfinger touch. Further, this inaccuracy in the prediction of the locationof the finger touch is a main reason why small electronic devices likethe smart phone have extreme difficulty in data entry into the text of aword processor or a spreadsheet, and makes the smart phone nearlyuseless for this purpose. Thus use in a business environment isrelegated to display operations of the programs represented by thevarious icons.

With respect to a notebook PC the cursor moving device is a touch padthat many users abandon for a PC mouse attached by an USB cable to thenotebook PC. Ease of use and positional accuracy of the cursor pointerare two of the reasons for the abandonment of the touch pad; although,there are users who have become adept at using the touch pad for theconvenience of not having to lug a computer mouse and the USB cableappendage in the mobile society for which the notebook PC was designed.Part of the problem is that the notebook PC touch pad has not kept upwith the resolution and speed of the display for the notebook PCrequiring the user to invoke several strokes on the touch pad to movethe cursor from one location on the display screen to another.

U.S. Pat. No. 6,392,632 (Lee) is directed toward an optical cursorcontrol device comprising an integrated camera, wherein captured imagesby an imaging device detects motion of the cursor control device. U.S.Patent Application No. 2005/0024336 (Xie et al.) is directed to the useof a Lambertian surface in a computer mouse to form a specularreflection, which provides an enhanced contrast to the image forpurposes of navigation. U.S. Patent Application No. 2005/0024623 (Xie etal.) is directed to the use of a Lambertian surface and a narrowbandwidth of light in a computer mouse to form a narrow bandwidthspecular reflection. U.S. Pat. No. 5,825,945 (Stolis et al.) is directedto an check imaging device using a Lambertian surface to project ahighly uniform and diffused beam to an imaging site.

Whether it is the touch pad of a notebook PC or the pointing inaccuracyinvolved with a touch screen of a portable device, there is a need for afast and accurate pointing control device for use with portableelectronic units. The pointing control device must be integral to theportable electronic unit and have the speed and accuracy to facilitatethe use of the portable electronic unit, such as the notebook PC, in thebusiness environment, where word processor documents and spreadsheetscan be easily created with accurate and easy data and word entry.

SUMMARY

It is an objective of the present invention to provide a sensitive andhigh resolution cursor maneuvering device for portable electronicequipment such as notebook computers.

It is further an objective of the present invention to form the cursormaneuvering device using a light source, a photo imaging device and asemi-transparent plate comprising a light diffusing surface such as aLambertian surface.

It is still further an objective of the present invention to provide thecapability to use multiple fingers contacting the light diffusingsurface, or Lambertian surface, to maneuver multiple objects or toinitiate operations in addition to the maneuvering of the cursor.

The present disclosure provides a cursor-maneuvering device formed by acavity covered by a semi-transparent plate containing a light diffusingsurface, wherein the cavity contains at least one light source and atleast one image sensor. The light diffusing surface, in particular aLambertian surface, can be a near perfect diffusing surface, where theintensity of the light emanating in a given direction from any smallsurface component is proportional to the cosine of the angle of thenormal to the surface. The brightness (luminance, radiance) of aLambertian surface is constant regardless of the angle from which it isviewed. The plate is semi-transparent to the degree that light fromeither side of the plate can be observed in a highly diffused state thatdoes not allow one to discern a shape of an object at a distance fromthe opposite side of the plate as a result of the Lambertian surface.The semi-transparent plate that covers the cavity disperses ambientlight falling on the Lambertian surface from the environment external tothe cursor maneuvering device as well as the light from the light sourcewithin the cavity and provides a diffused homogeneous appearance of theouter side and the underside of the plate. Images of distant objectsfrom the plate are diffused by the Lambertian surface to the degree thatthey are not distinguishable by the image sensor.

It should be noted: 1) The light source within the cavity is preferablyan LED device; however, other light sources can be used. 2) The imagesensor is preferably a CMOS imaging device capable of viewing the entireinside surface of the semi-transparent plate covering the cavity;however, other imaging devices capable of viewing the entire surface ofthe transparent plate to determine the location of the reflectance of apointing device can be used. 3) The surface of the semi-transparentplate is preferably a Lambertian surface formed with a fine grainsurface; however, other surfaces may be able replace the Lambertiansurface at a reduced performance, such as a course grain (rough)Lambertian surface, an etched surface or a frosted surface. It shouldalso be noted that although the aforementioned three preferred elementsof the present disclosure may have alternatives, the use of thesealternatives fall within the scope of the present disclosure.

When a pointing device, e.g. a finger, stylus or similar device,contacts the Lambertian surface of the semi-transparent plate, areflection of light from the light source within the cursor-maneuveringdevice produces an brightened image of the of the pointing device. Theimage sensor then detects this brightened image and follows thebrightened image as it is moved over the Lambertian surface from whichelectronics associated with the image detector provides control to acursor on the screen of an portable electronic device, e.g. notebook PC,cellular phone, global positioning system, gaming device, etc. Further,the pointing device can be lifted and reapplied to the Lambertiansurface to indicate selection of an element on the display of theelectronic device. Still further and especially in the case of thenotebook PC, multiple fingers can be uses in various predeterminedlocations on the Lambertian surface to perform functions in addition tocursor movement, e.g. scrolling, rotating an image, zooming in on thedisplay screen to provide high resolution and sensitivity for accuratepositioning of the cursor.

The image sensor is controlled to capture a plurality of images of thepointing device, preferably a finger. Within the plurality of images, afirst and a second image are segmented to extract motion vectors tocontrol the movement of a cursor on a display screen. In the case of theuse of a finger as a pointing device, the ridges, groves, curls andintersections of the fingerprint provide the definition that is trackedbetween the first and second image. The electronics coupled to the imagesensor segments the images and compares position changes that translateinto the motion vectors used to control the cursor on a display screen.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be described with reference to the accompanyingdrawings, wherein:

FIG. 1 is a diagram of prior art of a touch panel of a modern cellularphone;

FIG. 2A-2F are diagrams of the cursor-maneuvering device of the presentinvention;

FIG. 3 is a diagram of the effect of a pointing device contacting thesurface of the cursor-maneuvering device of the present invention;

FIGS. 4A and 4B are diagrams of the location of the brighten image ofthe pointing device of the present invention;

FIG. 5A is a diagram of the shape of the brightened image of a fingerthat is pressed onto the surface of the cursor-maneuvering device of thepresent invention;

FIG. 5B is a diagram demonstrating the touching of surface of thecursor-maneuvering device of the present invention;

FIG. 6 is a diagram of multiple touch point functions of thecursor-maneuvering device of the present invention;

FIG. 7 is a diagram of potential use of the cursor-maneuvering device ofthe present invention;

FIG. 8 is a diagram of the optical effects of a rough diffusion surfacewhen a pointing device is not in contact with the surface; and

FIG. 9 is a diagram of the optical effects of a rough diffusion surfacewhen the pointing device is in contact with the surface.

DETAILED DESCRIPTION

In FIG. 2A is shown a semi-transparent plate 10 of the present inventionthat has a Lambertian surface 11. An incident light impinging upon theLambertian surface results in reflected light, diffused reflected lightand diffused transmitted light. When light falls on a Lambertiansurface, the light is scattered such that the apparent brightness of thesurface to an observer is the same no matter the observers viewingangle, and the surface is isotropic, or uniform in all directions. Thesame is true with respect to the transmitted diffused light. In otherwords an observer underneath or at the bottom of the semi-transparentplate will also see a uniform appearance in all directions. It should benoted that the term “semi-transparent” means that although light can getthrough, the light is diffused to a degree that distant objects cannotbe interpreted or seen.

FIG. 2B shows a cavity 12 of the cursor-manipulating device of thepresent invention that is covered by the semi-transparent plate 10,which contains a Lambertian surface. The image sensor 13 views through alens a diffused light that is uniform in all directions resulting fromthe ambient light that is impinging on the outer Lambertian surface ofthe semi-transparent plate 10. There is no definition of any object thatis remote from the Lambertian surface.

In FIG. 2C a light source 14 in the cavity 12, preferably an LED,directs light to the semi-transparent plate. Again the Lambertiansurface scatters the light from the light source such that the portionthat is reflected is diffused and will have a uniform appearance to theimage sensor 13 in all directions. Further any light from the LED thatis transmitted by the semi-transparent plate will be a diffusedtransmission in which an observer beyond the surface of thesemi-transparent plate will not be able to discern the light sourceother than perhaps the brightness of the top surface of thesemi-transparent plate is slightly brighter.

FIG. 2D and FIG. 2E demonstrate the appearance of the underneath side 15of the semi-transparent plate 10 as seen by the image sensor 13, auniform appearance that has some light intensity. FIG. 2F is the view ofthe image sensor 13 where the addition of the effects of the impingingambient light and that of the light source has a diffused appearance onthe underneath surface 15 of the semi-transparent plate in which thediffused light is uniform in all direction with no discernible features.

In FIG. 3 is shown the effects of touching the Lambertian surface of thesemi-transparent plate with a pointing device, where the pointing devicecan be any number of items such as a stylus, rubber eraser on a penciland a finger 20 as a pointing device. When a pointing device, such as afinger 20, touches the surface of the semi-transparent plate, theambient light is blocked from impinging upon the surface of thesemi-transparent plate directly under the pointing device, and when thelight source 14 is not on or does not exist, the image sensor will see ashadow 21. When the light source 14 is added to the cavity 12, abrightened surface of the pointing device contacting the Lambertiansurface, hereafter designated the brightened pointer surface, will bediscernible by the image sensor 13. The addition of the effects of theambient light alone and the light source 14 within the cavity produces abrightened pointer surface 23 of the pointing device in contact with theLambertian surface that can be readily detected by the image sensor andanalyzed with respect to movement and location by the electroniccircuits associated with the image detector.

It should be noted that the detailed characteristics of the pointersurface of the pointing device contacting the Lambertian surface,brightened by the light source 14, are visible to the image sensor 13.For instance, if the pointing device is a finger, the details of thefingerprint, e.g. the ridges, groves, curls and intersections, areclearly detectable by the image sensor within the brightened pointersurface in contact with the semi-transparent plate. It is the details ofthe fingerprint within the brightened pointer surface 22 that the imagesensor 13 monitors to determine movement that is translated into acursor position on a display screen of an electronic device.

FIG. 4A demonstrates what the image sensor 13 of the cursor-maneuveringdevice sees when a pointing device, in this case a finger 20, touchesthe right side of the Lambertian surface of the semi-transparent plate10 when the light source 14 is illuminated. The surface of thesemi-transparent plate 15 facing the image sensor displays a brightenedsurface of the fingerprint 23 in contact with the semi-transparentplate. The brightened surface 23 is a result of light from light source14 being reflected back into the cavity from the finger 20 that ispressing the Lambertian outer surface of the semi-transparent plate 10.The remainder of the surface of the underside 15 of the semi-transparentplate surrounding brightened pointer surface 23 has a diffusedappearance resulting from the diffusion of both the ambient light andthe light source by the Lambertian surface.

If the finger 20 is moved to the left side of the Lambertian surface ontop of the semi-transparent plate 10, the brighten pointer surface 23will appear to the image sensor 13 to now be on the left side of thesemi-transparent plate as shown in FIG. 4B. If the finger 20 is kept incontact with the Lambertian surface as the finger is moved to the leftside, the image sensor will track the details of the finger touching thesurface of the semi-transparent plate 10 that form the brightenedpointer surface 23 as the finger 20 is moved from right to left. Theelectronics associated with the image sensor 13 will convert the trackof the details of the finger within brightened pointer surface 23 intocursor movement coordinates on the display screen of the electronicdevice to which the cursor-maneuvering device is connected.

If the finger 20 is first lifted from the Lambertian surface of thesemi-transparent plate, the image sensor will not detect anything untilthe finger is place down onto the Lambertian surface on the left side ofthe semi-transparent plate, where the brightened pointer surface 23 willappear under the finger on the left side.

FIG. 5A shows how the image detected by the image sensor 13 changes theshape of the brightened pointer surface 41 when the finger 40 is pressedrelatively hard onto the Lambertian surface 11 of the semi-transparentplate 10. Although the brightened pointer surface 41 is more ellipticalin shape, the electronics associated with the image sensor 13 is able todetermine the location of the pressed finger and translate that positioninto a location on the screen of the electronic device such as anotebook PC. It should be noted that the image sensor senses theremaining area of the underside 15 of the semi-transparent plate 10 asan area of highly diffused light that contains no recognizable elementsor features.

In FIG. 5B a finger pointer 40 is located by the brightened pointersurface 41 at time t1, which is translated into a cursor location on thedisplay screen of the electronic device, e.g. a notebook PC. At time t2the finger 40 is lifted to position 42 and the brightened pointersurface 41 is blurred beyond recognition and no longer seen by the imagesensor 13. The entire surface of the underside of the semi-transparentplate exhibits a uniform diffused light over the entire surface of theunderside of the semi-transparent plate with no distinguishablefeatures. At time t3 the finger 40 is brought back into contact with theLambertian surface 11 of the semi-transparent plate 10 and thebrightened pointer surface reappears, which can be seen by the imagesensor 13. In the mean time the cursor on the display screen of thenotebook PC remains stationary. When the finger 40 is reapplied to theLambertian surface, the act of removing the finger and reapplying thefinger is a tapping action on the semi-transparent plate and can be usedto signify the selection of the item under the cursor on the displayscreen, or if the finger immediately moves upon re-contact at time t3,the immediate movement can imply to the electronics couple to the imagesensor that the cursor is to be moved in the direction of the movementof the finger.

In FIG. 6 is shown the underside surface 60 of the semi-transparentplate 10 that is viewed by the image sensor 13. There are severalbrightened pointer surfaces that demonstrate that a first finger (orpointing device) 61, a second finger 62 and a third finger 63 aresimultaneously in contact with the Lambertian surface 11 of thetransparent plate 10. Although, only three finger contacts (pointingdevices) are shown, the number can be greater or less than the threethat are shown. The multiple fingers, or pointing devices, can be usedto control multiple events on the display screen of the electronicdevice, e.g. notebook PC, including multiple cursors. Or the multiplefingers could be used to control other functions of the electronicdevice.

There are several special areas designated on the underside surface 60of the semi-transparent plate that are recognizable by the coordinateelectronics couple to the image sensor. The first is an area 64allocated to scrolling the image on the display screen of the electronicdevice to which the cursor-maneuvering device of the present inventionis coupled. This scrolling area when entered by one of the fingers(pointing device) 61, 62, 63 allows the finger in the scrolling area 64to scroll through pages displayed on the notebook PC screen, similar tothe scrolling wheel on a computer mouse. The second area 65 is an areathat is used to rotate the image displayed on the screen of theelectronic device and the third area 66 shown is an area that provides ahigh resolution and sensitivity that is used, for instance, to positionthe cursor on the screen of the notebook PC onto a small area like aspread sheet cell, or a particular letter or word in a sentence of aword processor document. Other special areas that might be assigned tothe functions are equivalent to the standard right and left mousebuttons and/or some of the functions found on a computer keyboard.

FIG. 7 shows some of the electronic devices in which the cursormanipulating device of the present invention can be applied. Theseelectronic devices include but not limited to a notebook PC (laptop PC),a cellular phone similar to those that have a full display screen onwhich multiple icons can be displayed, a hand held game device that ispopular with young people and adults, and a GPS unit. It should be notedthat the area allocated to the optically activated cursor maneuveringdevice of the present invention is considerably smaller for the cellularphone, game device and the GPS unit than the area allocated to theoptically activated cursor maneuvering device (mouse pad) of thenotebook computer. This is necessary so as to not require these handhelddevices, cellular phone, game device and GPS unit, to becomesubstantially larger; however, it is within the scope of this inventionthat a larger sized optically activated cursor maneuvering device can belocated on the backside of the handheld electronic devices.

Further, the minimum area of semi-transparent plate comprising aLambertian surface of this invention can be at least as small as an areadescribed by a circle having a diameter of approximately one halfcentimeter. This is smaller than the size of most fingers that would beused on the handheld devices. There would not be any ambient lightimpinging on the surface of the Lambertian surface of thesemi-transparent plate when covered by a finger, and the light sourcewithin the cavity is the source of light to brighten the pointersurface, a finger. The features of the fingerprint, e.g. the ridges,groves, curls and intersections, are monitored by the image sensor todetect finger movement over the small semi-transparent plate area andthereby directing the cursor of the handheld devices. The shape of thesmall semi-transparent plate containing a Lambertian surface need not becircular, and can be rectangular, square or any other shape necessary tosatisfy the design of the handheld device.

Still further, the small optically activated cursor maneuvering devicedescribed herein for handheld electronic devices can also be used on anotebook PC, an electronic note pad, electronic tablet, tablet computer,e-book reader, electronic media player, or similar devices. It isconceivable that the optically activated cursor maneuvering devicedescribed herein could replace the computer mouse for desktop computers,eliminating the need for a computer mouse by substituting the cursormaneuvering device of the present invention for the computer mouse orintegrating the cursor maneuvering device with a keyboard or a displayscreen of the desktop computer.

When a light beam impinges on a surface, a portion of the light will bereflected, and the rest will be absorbed or transmitted. When thesurface is very smooth, the process of reflecting light is oftenreferred as specular reflection. When said surface is rough incomparison to the wavelength of light, the resultant behavior is calleddiffuse reflection. Both of these are extreme conditions, the reflectingbehavior of most materials that are encountered in the practical worldare somewhere between the two extreme conditions.

A Lambertian surface has a unique property, which is known as the cosineemission law or Lambert's cosine law, wherein when a perfect Lambertiansurface is viewed from any angle, it has the same radiance. This meansthat to an image sensor the object and background scene have the sameapparent brightness (or luminance). Most materials perform specularreflecting and diffuse reflecting simultaneously. The present inventionuses both characteristics for different occasions, such as fingertouching and non-touching.

In the present disclosure, Lambertian diffusion is a term associatedwith the bulk phenomenon of a material which blurs the contour of anobject by a diffused refection effect. Other optical effects such astransmission, absorption, scintillation, may accompany the diffusereflection effect. These effects may not be explicitly shown herein, butthe effects exist. FIG. 8 demonstrates an exemplary case of such aneffect. When a surface 802 is quite rough, the portion of light that canbe used for forming the clear images per the specular reflection effectis decreased. The diffuse reflection effect, on the other hand, ismanifested. This can be denoted by the multiple segments of light paths,i.e. paths A, B and C, D, respectively. Note that A and B are generatedby a light source 803 that directs a light L1 at the surface 802. Lightpath C and D are generated by ambient light L2. Despite L1 and L2 comefrom the opposite directions, they have similar diffuse reflectioneffect due to the Lambertian surface 802 being an isotropic—and reflectslight to all angles evenly. The finger 801, which is above but nottouching the Lambertian surface 802, is not seen by the image detector804 because a portion of the light from the light source 803 thatreaches the finger is reflected back similarly to the paths C and D ofexternal light L2 and as a consequence is highly diffused.

The situation shown in FIG. 8 will be changed when paths A and B areblocked. As FIG. 9 shows, paths A and B now are blocked by the finger801 which touches the Lambertian surface 802. It should be noted that inthe practical case, this Lambertian surface 802 can be made of thematerials that bear the property between the two extremes of specularreflection and diffuse reflection. So what is really blocked is thediffuse reflection, the specular reflection part can be preserved oreven enhanced. As FIG. 9 shows, being perturbed by the touching of theLambertian surface 802 with the finger 801, segments A and B no longerexist; the remaining reflecting path is F, which subsequently causes theintensity of the image (finger) generated by light source 803 anddetected by the image sensor 804 to be enhanced. As FIG. 9 also shows,the blurred image of the background which comes from the ambient lightL2 stays intact since the diffusion paths C and D stay intact. Accordingto the fundamental material science, the performance of the Lambertiansurface being used by the present disclosure is readily affected bysurface morphology (roughness, etc.), refractive index of the Lambertianplate and that of the medium touching said Lambertian surface. Otherfactors that deal with the transmission property of the media,reflection, and absorption, etc. may also affect the intensity of theimage seen by the image sensor 804.

With the aforementioned physical principles illustrated, the presentinvention is able to adopt the many ways to fabricate a non-perfectLambertian surface and still reach its ultimate goal of motiondetection. The rule of thumb is the same. By optimizing the surfacemorphology, refractive index, reflectivity, etc. of the Lambertianplate, the diffusion and reflection effect of the light diffusing plate(namely the Lambertian plate in the present disclosure) is controlled insuch a way that the intensity of the image of the object that is notengaged in touching the diffusion plate, such as a non-perfectLambertian plate, is blurred as viewed through the plate, and vice versa(not blurred) for that of the object being engaged in touching thediffusion plate. Typical methods comprise harnessing the surfaceroughness of the Lambertian plate, depositing an over-coating layer withhigher refractive index onto the light diffusing plate, or even pavinganother highly reflective layer over the Lambertian plate, etc. Thesemeans all fall into the essential spirit of the present invention.

It should be noted that any motion detection of a pointing devicethrough a transparent, or semi-transparent, plate containing a surfacethat diffuses light in such a way that a distant non-touching pointingdevice is blurred and difficult to detect, or non-detectable, while apointing device that touches the surface of the semi-transparent plateis non-blurred, or visible, and is detectable as viewed through theplate, and is within the scope of this disclosure.

While the disclosure has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade without departing from the spirit and scope of the disclosure.

What is claimed is:
 1. A cursor maneuvering device, comprising a cavitywithin which is located a light source and an image sensor, wherein saidcavity is covered by a semi-transparent plate having an outer surfaceand an inner surface and wherein said outer surface is a Lambertiansurface and wherein said inner surface is capable of being illuminatedfrom within by said light source and, when said illumination occurs,said illumination also strikes said Lambertian surface and a brightreflection is radiated from a pointing device moving arbitrarily whilein contact with said outer Lambertian surface wherein said brightreflection is characterized by a well defined contour that is detectableby said image sensor and is distinguishable from the contours of imagesformed by ambient illumination of arbitrary intensity and frequency frombackground objects external to said device and not in contact with saidLambertian surface and, thereby, said image sensor detects no welldefined contour patterns from said external objects and said brightreflection from said pointing device produces an electrical responsewith steady, high signal-to-noise ratio as said pointing device moveswhile in contact with said Lambertian surface, wherein said cursormaneuvering device is capable of controlling a cursor on a displayscreen of an electronic device coupled to the cursor maneuvering device.2. The device of claim 1, wherein said pointing device used to contactsaid Lambertian surface further comprises one of the following: a) afinger; b) a stylus; c) a pen; or d) a pencil.
 3. The device of claim 2,wherein multiple pointing devices in contact with said Lambertiansurface of the semi-transparent plate simultaneously control a multipleof functions on said display screen.
 4. The device of claim 3, whereinsaid Lambertian surface is portioned into special areas to allow controlof special functions, comprising at least: a) cursor control, includingcontrol of multiple cursors; b) page scrolling; c) image rotation, d)screen resolution; and e) equivalent right and left mouse buttons. 5.The device of claim 1, wherein said image sensor captures a plurality ofimages within which a first and a second image of the plurality ofimages are segmented to determine movement of the pointing devicebetween said first and second image and to extract motion vectors formovement of a cursor on the display screen.
 6. The device of claim 1,wherein said Lambertian outer surface of the semi-transparent plateblurs an image of said pointing device when said pointing device isremote from said surface so that said image is not detectable by saidsensor as having a discernable pattern and wherein said Lambertiansurface sharpens the image of the pointing device when said pointingdevice is in contact with said Lambertian surface to allow detection bythe image sensor, whereby a function located at a cursor location on thedisplay screen is selected by a tapping action of the pointing device onsaid outer surface, wherein the pointing device is lifted off the lightdiffusing surface of the semi-transparent plate to a point beyond itsrecognition by the image sensor, and is then brought back in contactwith the light diffusing surface to allow the pointing device to bedetected again by the image sensor and to thereby signify selection of afunction at the cursor location.
 7. A method of cursor control,comprising: a) providing an optical cursor maneuvering device, whereinsaid device comprises a cavity within which is a light source and animage sensor and wherein said cavity is covered by a semi-transparentplate having a Lambertian outer surface, wherein said semi-transparentplate is capable of being illuminated from within by said light source,whereby a pointing device touching said Lambertian outer surface of thesemi-transparent plate and moving arbitrarily thereon becomes visible tosaid image sensor as a bright reflection having an easily followedcontour and is distinguishable from the indefinite contours of imagesformed by ambient illumination of arbitrary intensity and frequency frombackground objects external to said device and not in contact with saidLambertian surface and, thereby, said image sensor detects no fixedpatterns from said external objects and; b) capturing a sequence ofimages of said pointing device while said pointing device is movably incontact with said light diffusing surface; and c) analyzing a set ofsaid sequential images of the pointing device and generating acorresponding signal with constant signal-to-noise ratio to producecorresponding movement of a cursor on a display screen.
 8. The method ofclaim 7, wherein tapping the semi-transparent plate with said pointingdevice selects functions on the display screen.
 9. The method of claim7, wherein said pointing device used to contact said Lambertian surfacefurther comprises one of the following: a) a finger; b) a stylus; c) apen; or d) a pencil.
 10. The method of claim 9, wherein multiplepointing devices, in particular, multiple fingers contact saidLambertian surface simultaneously to control multiple functions.
 11. Themethod of claim 7, wherein maneuvering said pointing device withindesignated areas on said Lambertian surface controls functions displayedon the display screen, comprising: a) controlling said cursor; b)scrolling a page on the display screen; c) rotating an image, d)adjusting screen resolution; and e) providing equivalent right and leftmouse buttons.
 12. The method of claim 11, wherein selecting functionson the display screen is accomplished by controlling the cursor to afunction displayed on the display screen and tapping said outerLambertian surface of said semi-transparent plate with the pointingdevice to select the displayed function, wherein tapping thesemi-transparent plate comprises moving the pointing device a distanceaway from the semi-transparent plate to blur the image of the pointingdevice beyond its recognition by the image sensor and then bringing thepointing device back into contact with the semi-transparent plate torestore its image and again allow the image sensor to detect thepointing device to select the displayed function.
 13. The method ofclaim 11, wherein controlling the display screen with the pointingdevice further comprises scrolling said display screen by moving thepointing device in a designated scrolling area on said Lambertiansurface of said semi-transparent plate.
 14. The method of claim 11,wherein controlling the display screen with the pointing device furthercomprises rotating an image on the display screen by moving the pointingdevice in a designated area for rotation on said Lambertian surface ofsaid semi-transparent plate.
 15. The method of claim 11, whereincontrolling the display screen with the pointing device furthercomprises increasing sensitivity and resolution of the display screen bymoving the pointing device in a special designated area on saidLambertian surface of said semi-transparent plate.
 16. An electronicdevice, comprising: a) a display screen; b) a maneuverable cursor onsaid display screen; and c) a cursor maneuvering device, coupled to thedisplay screen and capable of maneuvering said cursor on said displayscreen, said device comprising a cavity within which is located a lightsource and an image sensor, wherein said cavity is covered by asemi-transparent plate having an outer surface that is a Lambertiansurface through which a bright reflection from a pointing device movablyin contact with said outer Lambertian surface is detectable by saidimage sensor when an inner surface of said semi-transparent plate isilluminated by said light and wherein images produced by externalobjects not in contact with said Lambertian surface do not produce anidentifiable pattern that is detected by said image sensor, wherein asignal of high and constant signal-to-noise ratio generated by saididentifiable pattern produced by said image sensor of said cursormaneuvering device controls the cursor on the display screen.
 17. Thedevice of claim 16, wherein the pointing device is a finger, and whereinfeatures of a fingerprint of the finger are monitored by the imagesensor to detect movement, thereby controlling the cursor movement onthe display screen.